Immediate effects of vocal warm-up exercises on elementary teachers' voice

Introduction: Teachers are a large group of professional voice users who are exposed to many voice problems. Vocal warm-up exercises (VWUE) can prepare the muscles involved in vocalization before teaching and can reduce voice damage in teachers. However, limited studies have examined the effects of VWUE on teachers' voices. Therefore, the present study was conducted to investigate the immediate effects of VWUE on the acoustic and perceptual characteristics of the teachers' voices. Materials and Methods: The present study was a pretest-posttest within a group design study. A total of 20 teachers aged 18-45 with at least 5 years of teaching experience participated in the study and received VWUE for 30-45 minutes. VWUE included stretching the sternocleidomastoid, trapezius, and mylohyoid muscles, open-mouth, and yawn-sigh technique, glottal fry, tongue trills, resonance exercises, and performing ascending and descending tones. Outcome measurements included auditory-perceptual evaluation using CAPE-V and assessment of acoustic parameters with fundamental frequency, jitter, shimmer, and harmonic to noise ratio. Results: After VWUE, a significant improvement was observed in acoustic parameters including decreasing jitter and shimmer and increasing the harmonic to noise ratio during the vowel /ɑ/ sustaining (P<0.05). Also, no significant change was found in the fundamental frequency of teachers' voices (P>0.05). In addition, VWUE resulted in a statistically significant improvement and reduction in the overall severity of voice disorder during vowel sustaining and connected speech tasks (P<0.05). Conclusion: The present study can provide primary evidence of the immediate and positive effects of VWUE on teachers' voices. However, due to the lack of a control group in our study, the positive results of VWUE should be interpreted with more caution, and stronger studies with a control group are recommended in the future.